Background: Lumbar degenerative disease (LDD) is a chronic condition of the lumbar spine affecting the vertebrae, facet joints and intervertebral discs and commonly causing low back pain (LBP) which may be due to instability of the motion segment. Aim: to evaluate the relation between lumbar degenerative disease and lumbar instability. Patients and Methods: Sixty patients (20 females and 40 males) complained of LBP and/or sciatica. They were studied in 4 groups categorized according to MRI grading using Modified Pfirmann Disc Degeneration Scale: Group I (19 patients grade IV), Group II (16 patients grade V), Group III (14 patients grade VI) and group IV (11 patients grade VII). In addition to full history taking, all of them were subjected to thorough clinical examination including PVAS to assess pain severity, Routine lab. investigations and Radiological examination (X-Ray: Static and dynamic, CT and MRI). Results: No significant differences between four groups regarding clinical data (LBP, sciatica, full motor power or SLR) were found but SLR angles were lower than normal within all groups, while PVAS showed significant difference between four groups (P